eslint.config.mjs

import typescriptEslint from '@typescript-eslint/eslint-plugin';
import jsdoc from 'eslint-plugin-jsdoc';
import stylistic from '@stylistic/eslint-plugin';
import preferArrow from 'eslint-plugin-prefer-arrow';
import jest from 'eslint-plugin-jest';
import globals from 'globals';
import eslintPluginPrettierRecommended from 'eslint-plugin-prettier/recommended';
import tsParser from '@typescript-eslint/parser';

export default [
  {
    ignores: [
      '**/dist/**/*',
      '**/tsconfig.json',
      '**/tsconfig.eslint.json',
      '**/package.json',
      '**/package-lock.json',
      '**/renovate.json',
      '**/ort',
    ],
  },
  {
    files: ['src/**/*.ts', 'test/**/*.ts', 'dist/**/*'],
    plugins: {
      '@typescript-eslint': typescriptEslint,
      '@stylistic': stylistic,
      jsdoc,
      'prefer-arrow': preferArrow,
      jest,
    },

    languageOptions: {
      globals: {
        ...globals.node,
        ...jest.configs['flat/recommended'].languageOptions.globals,
      },

      parser: tsParser,
      ecmaVersion: 5,
      sourceType: 'module',

      parserOptions: {
        project: 'tsconfig.eslint.json',
      },
    },

    settings: {
      'import/resolver': {
        node: {
          extensions: ['.ts'],
        },
      },
    },

    rules: {
      ...jest.configs['flat/recommended'].rules,

      'jest/expect-expect': [
        'warn',
        {
          assertFunctionNames: ['verify', 'expect'],
        },
      ],

      '@typescript-eslint/adjacent-overload-signatures': 'error',

      '@typescript-eslint/array-type': [
        'error',
        {
          default: 'array',
        },
      ],

      '@typescript-eslint/dot-notation': 'error',

      '@stylistic/member-delimiter-style': [
        'error',
        {
          multiline: {
            delimiter: 'semi',
            requireLast: true,
          },

          singleline: {
            delimiter: 'semi',
            requireLast: false,
          },
        },
      ],

      '@typescript-eslint/naming-convention': [
        'error',
        {
          selector: 'default',
          format: ['camelCase'],
          leadingUnderscore: 'allow',
          trailingUnderscore: 'forbid',
        },
        {
          selector: 'variable',
          format: ['camelCase', 'UPPER_CASE'],
          leadingUnderscore: 'allow',
          trailingUnderscore: 'forbid',
        },
        {
          selector: 'enumMember',
          format: ['camelCase', 'UPPER_CASE'],
        },
        {
          selector: 'typeLike',
          format: ['PascalCase'],
        },
        {
          selector: 'import',
          format: ['camelCase', 'PascalCase'],
        },
      ],

      '@typescript-eslint/no-empty-function': 'error',
      '@typescript-eslint/no-empty-interface': 'error',
      '@typescript-eslint/no-explicit-any': 'error',
      '@typescript-eslint/no-floating-promises': 'error',
      '@typescript-eslint/no-for-in-array': 'error',
      '@typescript-eslint/no-misused-new': 'error',
      '@typescript-eslint/no-namespace': 'error',
      '@typescript-eslint/no-parameter-properties': 'off',
      '@typescript-eslint/no-this-alias': 'error',
      '@typescript-eslint/no-unnecessary-condition': 'error',
      '@typescript-eslint/no-unnecessary-qualifier': 'error',
      '@typescript-eslint/no-unnecessary-type-arguments': 'error',
      '@typescript-eslint/no-unnecessary-type-assertion': 'error',
      '@typescript-eslint/no-unused-expressions': 'error',
      '@typescript-eslint/no-use-before-define': 'off',
      '@typescript-eslint/no-var-requires': 'error',
      '@typescript-eslint/prefer-for-of': 'error',
      '@typescript-eslint/prefer-function-type': 'error',
      '@typescript-eslint/prefer-namespace-keyword': 'error',
      '@typescript-eslint/prefer-readonly': 'error',
      '@typescript-eslint/promise-function-async': 'error',

      quotes: [
        'error',
        'single',
        {
          avoidEscape: true,
          allowTemplateLiterals: true,
        },
      ],

      '@typescript-eslint/restrict-plus-operands': 'error',
      '@stylistic/semi': 'error',

      '@typescript-eslint/strict-boolean-expressions': [
        'error',
        {
          allowNullableObject: true,
          allowNullableBoolean: false,
          allowNullableString: false,
          allowNullableNumber: false,
        },
      ],

      '@typescript-eslint/triple-slash-reference': [
        'error',
        {
          path: 'always',
          types: 'prefer-import',
          lib: 'always',
        },
      ],

      '@typescript-eslint/explicit-function-return-type': [
        'error',
        {
          allowExpressions: true,
          allowTypedFunctionExpressions: true,
          allowHigherOrderFunctions: true,
          allowDirectConstAssertionInArrowFunctions: false,
          allowConciseArrowFunctionExpressionsStartingWithVoid: false,
        },
      ],

      '@stylistic/type-annotation-spacing': 'error',
      '@typescript-eslint/unified-signatures': 'error',
      'arrow-parens': ['error', 'always'],
      'brace-style': 'error',
      'comma-dangle': ['error', 'always-multiline'],
      complexity: 'off',
      'constructor-super': 'off',
      'eol-last': 'error',
      eqeqeq: ['error', 'smart'],
      'guard-for-in': 'error',

      'id-blacklist': [
        'error',
        'any',
        'Number',
        'number',
        'String',
        'string',
        'Boolean',
        'boolean',
        'Undefined',
        'undefined',
      ],

      'id-match': 'error',

      'jsdoc/check-alignment': 'error',
      'jsdoc/check-indentation': 'error',
      'linebreak-style': 'error',
      'max-classes-per-file': 'off',
      'max-len': 'off',
      'new-parens': 'off',
      'newline-per-chained-call': 'off',
      'no-bitwise': 'error',
      'no-caller': 'error',
      'no-cond-assign': 'error',
      'no-console': 'error',
      'no-debugger': 'error',
      'no-duplicate-case': 'error',
      'no-duplicate-imports': 'error',
      'no-empty': 'error',
      'no-eval': 'error',
      'no-extra-bind': 'error',
      'no-extra-semi': 'error',
      'no-fallthrough': 'error',
      'no-invalid-this': 'off',
      'no-irregular-whitespace': 'error',
      'no-multiple-empty-lines': 'error',
      'no-new-func': 'error',
      'no-new-wrappers': 'error',
      'no-redeclare': 'error',
      'no-return-await': 'error',
      'no-sequences': 'error',
      'no-sparse-arrays': 'error',
      'no-template-curly-in-string': 'error',
      'no-throw-literal': 'error',
      'no-trailing-spaces': 'error',
      'no-undef-init': 'error',
      'no-unsafe-finally': 'error',
      'no-unused-labels': 'error',
      'no-var': 'error',
      'no-void': 'error',
      'object-shorthand': 'error',
      'one-var': ['error', 'never'],
      'prefer-const': 'error',
      'quote-props': ['error', 'as-needed'],
      radix: 'error',
      semi: 'off',

      'sort-imports': [
        'error',
        {
          allowSeparatedGroups: true,
          ignoreDeclarationSort: true,
        },
      ],

      'space-before-function-paren': 'off',
      'space-in-parens': ['error', 'never'],

      'spaced-comment': [
        'error',
        'always',
        {
          markers: ['/'],
        },
      ],

      'use-isnan': 'error',
      'valid-typeof': 'error',
    },
  },
  eslintPluginPrettierRecommended,
];